Strings uneven MPPT Voltage

G

garty611

Hi all I have just had a 3920KW Sharp 16 X 245W panels fitted with a Solar River SR4K4TLA1 inverter.

There are 2 strings. One is currently reading around 330V and the other is just below 200V.

6 of the panels are landscape and 10 are portrait. I have since found out that 6 are on one string and 10 on the other.

Will that effect anything do you think or should the strings be matched in terms of input Volts.

The SolarRiver Product manual suggests that MPPT voltage range is between 200-500 V. The maximum DC Voltage is 550V. So therefore one of the strings falls below this minimum of 200V

Can anyone shed any light??
 
I'm not sure if the Solar River SR4K4TLA1 has two MPP trackers. If it doesn't, then you have problems.

The strings need to be the same if they are both installed on one MPPT.
 
They are not the same but if one falls below the minimum (200 V) will that effect total output.
 
I know its not the best system all round as I originally wanted 250W Sharp panels and a 3000 sunny boy inverter but it all changed when the Gov cut the FiTs... Has anyone had any experience with the SolarRiver stuff?
 
I've never used them.

However, if your installer has installed uneven strings and the inverter is indeed a single MPPT inverter then he has installed you a poor system. I've found a spec sheet but I'm not sure it is for the inverter that you have.

Having two inputs does not necessarily mean two MPPTs
 
I understand cheers BiggsSolar, I'm trying to get them back ASAP as the roofer set the strings without telling the sparks (i'm led to believe). I know now that they need to be sorted.
 
garty611 said:
I know its not the best system all round as I originally wanted 250W Sharp panels and a 3000 sunny boy inverter but it all changed when the Gov cut the FiTs... Has anyone had any experience with the SolarRiver stuff?
Click to expand...

I wouldn't worry about Sharp being the best, we've got Sharp and lots of panels we install often outperform them/ SB3000 is under spec for that size system too imo.

On a more positive note - you've got panels installed and although you need a bit of reconfiguring with the strings you're installed and hitting the 43p - happy days :-)

It could be worse - you could be an installer. :rofl:
 
SRE said:
I wouldn't worry about Sharp being the best, we've got Sharp and lots of panels we install often outperform them/ SB3000 is under spec for that size system too imo.

On a more positive note - you've got panels installed and although you need a bit of reconfiguring with the strings you're installed and hitting the 43p - happy days :-)

It could be worse - you could be an installer. :rofl:
Click to expand...

No I've still got Sharp 245 I wanted the Sharp 250's but beggars cant be choosers this late on eh?
 
Some installers insist that landscape and portrait panels shouldn't be installed on the same string but I'm unconvinced. They definitely need to be on a 8 + 8 configuration.

To be honest, I would say that a lot of the installs that have been carried out over the last few weeks will have similar issues.

Standards and good designs appear to have gone completely out of the window.
 
BiggsSolar said:
Some installers insist that landscape and portrait panels shouldn't be installed on the same string but I'm unconvinced. They definitely need to be on a 8 + 8 configuration.

To be honest, I would say that a lot of the installs that have been carried out over the last few weeks will have similar issues.

Standards and good designs appear to have gone completely out of the window.
Click to expand...

Cheers guys for all your help I'll keep you posted what happens!!
 
I was just wondering how are you measuring the voltages on the two strings, is it a function of the inverter? or are you simply turning off each of the DC isolators in turn. If the inverter has the ability to measure voltages on each string independently then it might have some clever optimization system even though the documentation I've found says it only has one MPP tracker.
 
JohnBoyZ said:
I was just wondering how are you measuring the voltages on the two strings, is it a function of the inverter? or are you simply turning off each of the DC isolators in turn. If the inverter has the ability to measure voltages on each string independently then it might have some clever optimization system even though the documentation I've found says it only has one MPP tracker.
Click to expand...

Good question... I was reading the Electricians meter whilst he was testing the system as originally he got the polarisation the wrong way around!! I may add that both strings are on the same DC isolator is that wrong?? Will it effect anything??
 
There are many ways to configure the isolators I always like one isolator per string, you say there are 4 DC wires going into the inverter so maybe its a 4 pole isolator?
 
I was installing solivia inverters last weeks with 4 pairs of inputs on it, bit one MPP tracker so its irrelevant how many inputs are there.
Its also down the the installer how many isolators/ wires etc are arranged in what way.
 
yellowvanman said:
Don't want to throw another spanner in the works but Sharp don't like their panels secured on the short side when in landscape.
Click to expand...

I know its not ideal because of drainage etc but also read on here somewhere it doesnt matter too much (its the only way to get 16 panels on the roof)
 
Last edited by a moderator:
They can be fitted landscape but some panels cannot be clamped on the short sides as it will invalidate the warranty. Vertical rails are required.

I'm not sure if this is the case with Sharp panels. I know it used to be the case but I haven't used them for a while. Does anyone know if Sharp have changed their spec with regards to clamping the panels?
 
Just had a look at the installation guide. They can't be clamped on the short side but can be installed on verticals and clamped on the long side or can be cross railed. So it depends on how they've been fitted. You should be able to see where the clamps are - if they are on the short side your warranty will be void if they are on the long side the installer must have either cross railed or used verticals.
 
Cheers guys whole thing is a mess!! Anyone know what grounds I have for a refund/action taken!!
 
I think your best course of action is to work with your installer. We've all been under unbelievable pressure for the last few weeks and mistakes can happen. The last thing you need is a load of aggro and a system that's not working properly for the next few months.

I'd put in writing your concerns and ask your installer to visit next week when the dust has started to settle to discuss how things can be put right. Once the pressure is off next week you should get a reasonable response and a timely modification to your system.

I'm not condoning what's happened, but I can see how it might have happened and if you get it sorted you're one of the lucky ones to have got an excellent price for installation at the 43p fit rate. The 20 or so customers I had to turn away because we couldn't fit them in would rather be in your shoes.

Funny old world at the minute :-(

If you don't get sorted take it to REAL and Consumer Direct but please give the installer the chance to put it right first.
 
Garty,

Can you say how you get on with sorting out the short side fixing. I have the same issue, the other way round (10 portrait, 6 landscape) and think that the short side fixing of the 6 is a problem.

My thread is "Worrying incompetance or just minor niggles in the last minute rush??" sorry - not sure how to link yet!
 

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Strings uneven MPPT Voltage
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